The present invention relates to an apparatus and to instruments for frameless stereotactic surgery and computer aided surgery.
Various type of apparatuses are known for precisely positioning and for orientating a surgical instrument with relation to a patient""s skull. The instrument may be inserted into the brain down to a precise location for taking a biopsy or for recording an epileptic site by an electrode of for other similar surgical procedures.
In an article published in the Journal of Applied Neuro-Physiology, Volume 46, pages 272 to 275, (1983) and entitled xe2x80x9cA new headclamp for stereotactic and intracranial proceduresxe2x80x9d, Andrxc3xa9 Olivier, M.D. one of the present co-inventors and Gilles Bertrand, M.D. describe a semi-circular headclamp to be fixed to the patient""head for stereotactic and intracranial procedures. This headclamp, which is a part of the apparatus in accordance with the present invention, was then used in combination with the previously known Leksell stereotactic frame.
An advertising leaflet published in 1965 and entitled xe2x80x9cAccessories for neurosurgeryxe2x80x9d, describes a headclamp made of two pivoted parts with three spring loaded pins to engage the patient""s skull and secure the headclamp in position on the skull. This headclamp, made by American Sterilizer is designed for use with three basic neuro attachments more particularly illustrated in the document.
U.S. Pat. No. 4,465,069 dated Aug. 14, 1984, entitled xe2x80x9cCranial insertion of surgical needle utilizing computer-assisted tomographyxe2x80x9d, inventors: Jean-Yves Barbier and Christopher J. Moran describes a ring secured to the patient""s head by rubber cushions and secured to the operating table by a ring mount. An instrument guide is adjustably supported by the ring.
U.S. Pat. No. 4,805,615 dated Feb. 21, 1989, entitled xe2x80x9cMethod and apparatus for performing stereotactic surgeryxe2x80x9d, inventor: Mark P. Carol, describes and illustrates a positioning fixture which is designed to be secured to the patient""s skull by means of self-tapping screws. The positioning fixture carries a ball collet which can be secured in any selected orientated position by a set screw. The ball collet has a through bore for slidable insertion of a surgical instrument, such as a pin.
U.S. Pat. No. 4,955,891 dated Sep. 11, 1990, entitled xe2x80x9cMethod and apparatus for performing stereotactic surgeryxe2x80x9d, inventor: Mark P. Carol shows basically the same positioning device as in the previously noted U.S. Pat. No. 4,805,615.
U.S. Pat. No. 5,443,464 dated Aug. 22, 1995, entitled xe2x80x9cExternal fixator apparatusxe2x80x9d, co-inventors: Thomas A. Russell and Harry E. Lee Jr., describes an apparatus for stabilizing bone fractures which includes a double chuck with ball collets and retaining nuts, to receive two retaining pins. Each ball collet has slits and both the axial position and the orientation of a pin is locked by a single retaining nut.
U.S. Pat. No. 5,618,288 dated Apr. 8, 1997, entitled xe2x80x9cStereotactic system for surgical proceduresxe2x80x9d, inventor: Antonio M. Calvo, describes a frame which is secured to the patient""s head by a plurality of fixing screws and which supports an arc-shaped member on which a slider is mounted to guide and hold a surgical instrument.
U.S. Pat. No. 5,649,936 dated Jul. 22, 1997, entitled xe2x80x9cStereotactic guide apparatus for use with neurosurgical headframexe2x80x9d, inventor: Douglas D. Real, describes another type of apparatus for guiding a surgical instrument with precision within the patient""s skull.
U.S. Pat. No. 5,695,501 dated Dec. 9, 1997, entitled xe2x80x9cApparatus for neurosurgical stereotactic proceduresxe2x80x9d, co-inventors: Mark Carol, James L. Day, Erik G. Miller and Robert J. Riker, describes an apparatus for guiding a surgical instrument to a selected target within a patient""s skull and along any selected path. The apparatus includes a positioning device similar to the one described in previous noted U.S. Pat. Nos. 4,805,615 and 4,955,891, and a headclamp to secure the patient""s head with respect to the operating table or chair. An articulated arm is secured to the headframe and supports at its distal end a probe holder which has a ball and socket mechanism and an adjustment ball; probe holder may be maneuvered about a patient""s head and selectively locked into position for path evaluation, surgical instrument guidance or attachment of the hemispheric system. However, this arrangement does not provide a positioning device which may position with great precision a surgical instrument with its tip at a desired target within the patient""s brain.
The general object of the present invention is to provide a frameless stereotactic guiding system which has maximum accessibility to all the surface of the patient""s skull.
Another object of the present invention is to provide a guiding apparatus of the character described which provides for skull penetration at two or more locations at the same time and with great precision, thanks to a computer assisting assembly.
Another object of the present invention is to provide an apparatus of the character described which is very easy to manipulate.
Another object of the present invention is to provide a chuck to hold a surgical instrument in a precise spatial position.
Another object of the present invention is to provide a chuck which is used as a guide for precise and safe skull penetration by a surgical instrument.
Another object of the present invention is to provide a double chuck which uses one chuck for holding a stabilizing pin while a surgical instrument is guided through the other chuck.
Another object of the present invention is to provide a chuck in which an instrument orientation is set by a first locking device and an instrument axial position is set by a second, independently actuated, locking device.
Another object of the present invention is to provide a double chuck to which a stabilizing stop pin can be secured in one chuck while guiding a drill through the other chuck.
The frameless stereotactic apparatus of the present invention comprises a rigid half circular headclamp, at least three fixation pins carried by said headclamp spaced from one another and extending inwardly thereof toward the center of the latter, said fixation pins for application to a patient""s skull to secure said clamp on said skull in outwardly spaced position therefrom, a connector carried by one end of said clamp to firmly secure said clamp to a patient support surface, an articulated arm having a proximal end and a distal end, an attachment device carried by sad proximal end and securing said articulated arm to said headclamp, a double chuck device secured to the distal end of said articulated arm, said articulated arm including arm sections and clampable joints to secure said chuck in any spatial position close to said patient skull, said chuck including a body, a ball collet in said body, said ball collet capable of axially guiding an elongated surgical instrument, a first locking device to releasably lock said ball collet in a selected orientation and a second locking device to releasably lock said elongated instrument in a selected axial position, said first and second locking devices actuated independently of each other.
Preferably, said clamp has a plurality of spaced inwardly threaded through bores extending radially toward the center of said headclamp, said attachment device capable of being secured into any one of said through bores.
Preferably, said fixation pins have an externally threaded cylindrical body capable of being secured into any one of said through bores.
Preferably, said fixation pins include a spring loaded ratchet device to limit the pressure exerted by said pins on the patient""s skull.
Preferably, said connector is a starburst connector.
The present invention is also directed to a stereotactic guide apparatus for use with a neurosurgical headclamp and comprising an articulated arm having a proximal and a distal end, an attachment device carried by said proximal end for securing said arm to said headclamp, a double chuck device secured to the distal end of said articulated arm, said arm including arm sections and clampable joints to secure said chuck in a predetermined spatial position close to a patient""s head, said chuck including a body, a ball collet freely rotatable about its center in said body, said ball collet capable of axially guiding an elongated surgical instrument therethrough, a first locking device to releasably lock said ball collet in a selected orientation and a second locking device to releasably lock said elongated instrument in a selected axial position, said first and second locking devices actuated independently of each other.
The present invention is also directed to a double chuck for neurosurgical stereotactic procedures which comprises a body, a body extension to firmly secure said body to the distal end of an articulated arm, the body having a quadrangular cross-section with opposite base faces and two opposites side faces, a cylindrical body cavity having a first, circular, cavity opening at one of said two base faces, a cover plate removably covering the other one of said two base faces and having a second, circular, cavity opening in register with said first cavity opening, said first and second, circular, cavity openings having a smaller diameter than the diameter of said cylindrical body cavity, a ball member having a diametral through bore, located in said body cavity with a sliding fit and free to rotate about its center, a ball tightening member carried by said body, and protruding from one of said side faces to clamp said ball member in a selected oriented position of its through bore, a sleeve extending within said through bore and firmly secured to said ball member, said sleeve having an externally threaded, longitudinally slit, free end portion protruding from said body through at least one of said cavity openings and a locking nut surrounding and threaded on said free end portion and having an interfering fit with said slit free end portion to clamp in a selected longitudinal position, a surgical instrument of a cross-sectional size and shape to have a sliding fit with the inside of said sleeve, whereby the precise orientation and the longitudinal position of said instrument relative to said body can be successively and independently effected by respectively actuating said ball tightening member and said locking nut.
Preferably, there are two chucks, as above defined, disposed side by side within said body.
The present invention is also directed to a fixation pin for attaching a headclamp on a patient""s skull during stereotactic surgery and comprising an externally threaded cylindrical body having a proximal end and a distal end, a pointed tip forming said proximal end, a pair of annular cooperating sets of ratchet keys coaxial with said body, one set forming said distal end of said body, the other set forming a floating annular member, a guiding rod on which said other set is axially guided and keyed, said guiding rod axially moveable, guided by and rotatably mounted within said end of said body, a cylindrical externally threaded enlargement, outwardly spaced from said floating ring and secured to said guiding rod, a compression spring surrounding said guiding rod intermediate said enlargement and said floating ring and urging the latter into engagement with said one set of ratchet teeth, an operating sleeve-like knob screwed on said enlargement, freely surrounding said sets of ratchet teeth and rotatably engaging said body and a locking screw to secure said operating knob in an axially adjusted position on said guiding rod, whereby the compression force exerted by said compression spring on said floating annular member can be adjusted.
The invention is also directed to a ruler guide for use during stereotactic procedures comprising a body having first and second parallel end faces and a through bore normal to said end faces, a tubing fixed to said body and protruding from said first end face in a first direction, said tubing coaxial with and communicating with said through bore, a graduated ruler strip secured to said body and protruding from said second end face in a second direction opposite to said first direction, said strip having an edge parallel with and close to the axis of said through bore, said ruler strip calibrated to indicate the distance from said second end face of a selected point on a surgical instrument inserted within said through bore and within said tubing.
The invention is also directed to a twisted drill for fitting the rotatable chuck of a hand held power drilling tool comprising a helically fluted cylindrical body with a rotatably chuck engaging head, said body adapted to slidably fit within a guiding sleeve, said head inwardly tapered toward said body and defining a distal free edge which is solely gripped by said rotatable chuck so that said body may become inclined relative to the rotating axis of said rotatable chuck.
Preferably, said head has a polygonal cross-section.
Preferably, a stop collar surrounds and is slidable on said body and a manually actuated releasable clamping device is carried by said collar to releasably clamp said collar in a longitudinally adjusted position on said body.
The invention is further directed to a scalp punch for use in stereotactic surgery, which comprises a cylindrical rod having a proximal end and a distal end, said proximal end defining a central recess with an annular cutting edge surrounding said recess.